I basically have a tire shop in my garage. I bought the 21" wheel/tire package for wife's 2010 x5d, to replace the dunlops ($650/tire) I was able to find 20" bmw wheels on ebay and equipped them with conti DWS for same price as 21" tires only. My x5d has Bridgestone 20" Duelers......No comparison, Conti's are the best. Keep in mind, they are not run flats. Spoke to my mechanic at BMW and he is not a fan of RFT. He said put a small air compressor in trunk with a can of green slime (sealant). Again, I can't stress how much better of a ride the conti's have over the Duelers....